Geneqco

Yeah, I have a high flow metal cat (200 cell... 100 cell are also readily available now) and it makes a huge difference to the exhaust gas... I can tell just by walking behind the car when its running... so it's obviously doing something!

333pg333

Scott, maybe you can get Tim's take on this, I don't really mind either way so long as it's not a waste of time or money. I'll either pony up for a very good one or not at all.

gcb951

I tried driving with a cat in my car. All he did was meow constantly. I think he may have peed in the car too.....j/k

TRP951

well around here is just the yearly inspection and thats all. The race gas comment was just that race gas smells good burning it not that it is clean or anything

Cory9584

race gas does kill cats though

philcav7

And that damn hair, how can an animal possible shed so much and not be bald?

I have heard 'dyno' testing on a stock 951 to yeild a 15-20HP increase with a cat delete. HP yeilds were minimal using 3" exhaust/high flow muffler on a stock car with cat. Modified cars should yeild as much if not more HP increases.
High flow cat vs. no cat should be less of a difference when comparing to a clogged up 20 year old part.
A gutted cat is an option for those that are subject to visual inspections but will be no benefit for a sniffer test.

thingo

As long as you use a quality cat I don't think it affects your performance enough to compensate for the size of the potential fine, and once the cops defect you I would expect they would look over the rest of the car.
And those flames aren't that subtle

Cory9584

a gutted cat isnt as good as no cat, if you absolutely must have something there take an old cat, cut the ends off and open the ends to 3in, Then clean it out and stick your testpipe through it and weld it in place.

333pg333

Yep, I think I'm heading this way Rod. I'll check out the removable option. Hopefully best of both worlds for street and track.

Keithr726

My car came with two newer "high flow" cats installed. I still can figure out the damned brand. Anyway, after my smog check (every other august) I installed a testpipe and noticed quicker spool up with a noticeable increase in power and my car is running on minimal boost with a failing wastegate. Without the cats the car sounds much nicer and louder. The interior stays somewhat cooler so I feel that it does significantly decrease EGT. However the smell can be bad and when holding a paper towel behind the exhaust it stays white for about 30 seconds, then again I'm running quite rich. When smog comes up next august I will reinstall my testpipe after for the better sound, power, and lower temps.

tell me this is not restrictive and a source for high heat

333pg333

Sorry to ask a stupid question, but what is a 'test pipe'? We don't use the same terms down here. Are you saying that the 'test pipe' replaces the Cat? What does it do in comparison to the Cat? I just need for the stuff that comes out of my exhaust to pass whatever the test is. It appears that some say that even with a recent Cat I won't achieve that? What is a Race Cat? Should I just get a replaceable pipe that is Cat for the road and straight through for the track?

TRP951

A testpipe is pretty much just a catless pipe

Luis de Prat

To add another possibility, IIRC there's also a "cat bypass" ...

hosrom_951

To be very honest, we all should have cat's in our cars. Reduce those green house gases, we will regret not doing so in the future, since every bit helps.

Currently i don't have a cat, and that is the way i got my car (one muffler in the rear and that's it), but when i do upgrade to 3" exhaust, i will go for a cat. The car's emissions are very clean, the inspectors locally says that the co2 level in my car is as clean as the todays cars, and mine is an 86, which he said was very impressive.

Sure,m you MAY get less power, more back pressure and so on, but dedicated track cars are not driven daily (most of them) and off road use, so no cats is ok, DD cars really should....

my opinion.

S2cab

For 3 rwhp it doesn't make sense to eliminate it. IIRC, Random's cats aren't that much money either.